Metallized disazo dyes



Patented Mar. 3, 1953 METALLIZED DISAZO DYES' Joseph H. Trepagnier, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Application February 24, 1951, Serial No. 212,669)

8 Claims.

This invention relates to dyes which are useful in coloring cotton and regenerated cellulose, and more particularly to a new class of light-fast, water-soluble, blue-gray azo dyes.

Many of the gray dyes which are now known and which may be used in the coloring of cotton and regenerated cellulose are deficient in fastness properties, especially in fastness to light. Lack of light fastness is of importance when the dyes are used to color wearing apparel, automobile upholstery, draperies and the like. Furthermore, in recent years many cotton and rayon fabrics are after-treated with creaseproofing agents such as melamine-formaldehyde and urea-formaldehyde resins. Such creaseproofing agents frequently X NH affect the shade andlight fastness of the dyes with which the fabrics have been colored.

It is an object of this invention to provide a new These objects are accomplished by a new class of gray metallized disazo dyes having the formula:

in which at least one of X, Y, X and Y is a sulfonic acid radical, no more than one sulfonic acid radical being attached to the same aromatic nucleus, and in which the others of X, Y, X and Y are members of the class consisting of hydrogen and methyl, no more than one methyl group being attached to the same aromatic nucleus.

These dyes are made by coupling tetrazotized dianisidine with gamma acid, i. e., 'l-amino-lnaphthol-3-sulfonic acid, in which the amino group carries the appropriate aromatic substituent, and thereafter copperin the coupled dye.

One useful group of dyes falling within the general formula are the tetrasulfo disazo dyes made by coupling tetrazotized dianisidine with two moles of N-sulfophenyl gamma acid or N- sulfotolyl gamma acid in which the sulfo and methyl groups are in the meta or para positions, and thereafter coppering. The formula of these compounds is:

in which one of X and Y is a sulfonic acid radical and the other is a member of the class consisting mole of N-sulfophenyl or N-sulfotolyl gamma acid in which the sulfo and methyl groups are in the meta and para positions and thereafter coppering. The formula of these compounds is represented as follows:

Example 1 64 parts of gamma acid (7-amino-l-naphthol-' 3-sulfonic acid) in the form of an aqueous paste are added in portions, with stirring, to enough Water to make a total of 267 parts of water including that present in the gamma acid paste. 48.5 parts of sulfanilic acid are added to the mixture. This slurry is made permanently alkaline, as tested on Brilliant Yellow test paper, by the addition of 30% sodium hydroxide solution. On becoming alkaline, the slurry changes to a solution. The alkaline solution is run into an autoclave. The autoclave is sealed and flushed three times with sulfur dioxide. Sulfur dioxide is' then added to the charge until 35.3 parts have been absorbed. The charge is heated to 140 i 5 C. during a period of three to four'hours and is held at this temperature for 12-15 hours. The charge is then cooled to 90-95 C., any remaining pressure is vented and hydrated lime is added to the mixture until the pH is 11-11.5. This mixture is held at 90-95 C. for 8 hours and is then filtered while hot to remove calcium sulfite. The filtrate, which contains the desired product, is adjusted to pH 5 to 7 by the addition of 78% sulfuric acid. The solution is clarified by stirring with 13.4 parts of activated carbon and filtering. This solution, containing about 15% of N-p-sulfophenyl gamma acid, is retained for use in preparing one of the dyes of the invention. This compound has the formula:

on g

noas- SO3H If an equal amount of metanilic acid (m-aminobenzenesulfonic acid) is substituted for the sulfanilic acid employed in this example, N-(m-sulfophenyl) gamma acid is obtained, having the formula:

NH- soiH Example 2 4 dioxide is introduced at 2530 C. by alternately increasing the pressure to 40-50 pounds per square inch and letting it drop oil to 20-30 pounds. This operation is continued until 195 grams of sulfur dioxide are absorbed. The charge is heated to 135-145" C., while venting any pressure over 50-55 pounds, and held at this temperature for 17 hours. The charge is cooled to 90-95 C. and the pressure is released. Hydrated lime is added in small portions until the mixture gives an alkaline test on phenolphthalein paper. The mixture is agitated at 90-100 for 4 hours to release ammonia.

' It is then filtered and the cake of calcium sulfite is washed with water. The filtrate and washings the charcoal the solution is filtered and cooled to 20-25 C. For each parts of solution 15 parts of salt are added with agitation. The light tan colored precipitate is filtered off and dried. The

product is 7 (4-methyl-3-sulfoanilino) -1 -napthol- 3-sulfonic acid, or N-(m-sulfo-p-tolyl) gamma acid, and has the formula:

In the following examples, these substituted.

gamma acids are used to prepare theazo dyes of this invention. In each case, .quantitiesiare given as parts by weight.

Example 3 244 parts of dianisidi-ne in3000 parts of waterare acidified with 97 parts of hydrochloric acid and 154 parts of sulfuric acid. The resulting solution is cooled to 20 C. by the addition of 2000 parts of ice and is then tetrazotized at 20-25 C. with 138 parts of sodium nitrite, with a tenminute end point on starch-iodide test paper. The resulting solution of tetrazotized dianisidine is clarified by means of activated carbon and the exce s nitrite present in the solution is neutralized by the addition of sulfamicacid.

950 parts of N -p-sulfophenyl gamma acid,- prepared as a solution according to the methodof' Example 1, are diluted with Water to a volume of 10,000 parts by weight. The resulting solution is made slightly alkaline-to Brilliant Yellow test paper by adding a small amount of sodium hydroxide. 424 parts of sodium carbonateare added and dissolved and the solution is cooled to 10 C. by adding about 1,000 parts of ice. 'The dianisidine tetrazo solution is then run into the alkaline N-p-sulfophenyl gamma acid solution with rapid agitation. An excess of the sodium salt of N p=sulfophenyl gamma acid and'apH or 8 to 9 are'maintained throughout the coupling process. I

When the coupling reaction is complete, the resulting blue-black slurry is heated to 70 C. and 4,000 parts of common sa-lt are'added. The charge is filtered and the filter cakeis-washed with 20% salt solution to remove the excess'of the sodium salt of- N-p-sulfophenyl gamma'acid. The filter cake from the coupling reaction is then dissolved in 15,000 parts of water at 50-60 C. and 2,500 parts of salt and parts of ammonia (in aqueous solution) are added. 500 parts of copper'sulfate crystals dissolved in 2,000 parts of water are added and the charge is heated to I 6 95 C. and maintained at 92 2 C. fonsix'hours. place of N-m-sulfophenyl gamma'a'cid. The re- Phenolphthalein alkalinity and an excess of copsulting gray dye is similar in shade and in dyeing per are maintained throughout the coppering and fastnessproperties to that prepared accord-.- process. The coppered product is obtained as ing to the procedure of Example 5. Its formula a dark slurry which is filtered and washed with 5 is:

% salt solution. The filter cake is air-dried In the same manner, other dyes may. be preat 80? 0. 1,500 parts of dry product are obtained, pared by coupling tetrazotized dianisidine with having the formula: two moles of N-(p-sulfo-m-tolyl) gamma acid;

If an equal amount of N-m-sulfophenyl gamma acid is substituted for the N-p-sulfophenyl gamma acid in the coupling reaction, a dye is obtained which has very similar properties. Its formula is:

1103s Q-NH- N==N N=N NH sour sous: BOSS Example 4 An equivalent amount of N-(m-sulfo-p-tolyl) Np'tolyl gamma acld and one gamma acid is used in place of the N-p-sulfo- 0f N-p-slllfophenyl, p y N- pphenyl gamma acid used in Example 3, and a dye sulfo-m-tolyl) or N-(m-sulfo-p-tolyl) gamma is obtained which has similar dyeing and fastness a id; or it one mole of N-p-sulfophenyl properties. The formula of this dye is:

Cu 0 O--Cu---O x l 5 l 45 sulfophenyl, N-(p-sulfo-m-tolyl) or N-(m-sulfo- 244 parts of dianisidine are tetrazotized as in p-toyl) gamma acid and with one mole of a dif- Example 3. Sodlum carbo added to Ierent N-sulfophenyl or N-sulfotolyl gamma acid until the pH is 4.0 to 4.5.

A Solution of 315 parts of NmhemlEamma; from this same group of compounds. In each acid and parts of sodium hydroxide in 4000 case the coupled dyestuff is coppered to form parts of Water is added to the tetrazo solution e fi l pr t l Of t ese c pou ds are together with enough sodium carbonate to keep ray, light-fast dyes.

the pH at to Thls amount of N'phenyl The most convenient method of coppering the gamma acid is sulficient to form a monoazo coupling with dianisidine. There is then added a cmpled dye'stufl usually employ an excess solution of 475 parts of N-m-sulfophenyl gamma of copper sulfate in a solution made alkaline acid, prepared as in Example 1, together with with ammonia. It is also possible to use other enough sodium carbonate to bring the pH up to copper compounds, such as copper acetate, in

e i' productis salted out filtered and place of copper sulfate and to use organic amines converted to the copper compound just in in place of ammonia. Suitable amines are pyr- Example 3 y idine, the picolines, ethanolamine, diethanol- The dye obtained in this example is similar to amine, triethanolamine, methylglucamine, trithose obtained in Example 3, but the dyeing is (hydroxymethyl) aminomethane 1 3 diami 55 inoi igfig Shade of blue Thls dye has the propanol-2, morpholine and the like.

with one mole of N-phenyl gamma acid and one mole of N-p-sulfophenyl gamma acid or N-(psulio-m-tolyl) gamma acid; with one mole of Example 6 The procedure outlined in Example 5 is liepeated usingN-(m-sulfo-p-tolyl) gamma acid in The same final coppered dyes are obtainable if 3,3'-dihydroxybenzidine is used in place of diatom-i431 8 anisidine, but the coupling reactionpro'ceeds less I claim:

smoothly and easily than when dianisidine is 1. The coppered disazo dyes having the used and poorer yield and purity are obtained. formula:

X NH N=N- N= NH -x' Y soar! HOaS- Y It is therefore desirable to start the synthesis in which at least one of X, Y,'X' and Y is a with dianisidine. V l sulfonic acid radical, no more than one sulfonic The dyes of this invention color cotton and acid radical being attached to the same aromatic regenerated cellulosic materials pleasing blue- 15 nucleus, and in which the others of X, Y, X and gray shades of excellent light fastness. They Y are members of the class consisting of hydrohave the unexpected advantage that their light gen and methyl, no'more than one methyl group and fastness properties are unafiected by subbeing attached to the same aromatic nucleus. sequent creaseproofing of the fabrics. The dyes 2.The coppered tertrasulfo disazo dyes having have good wash fastness, discharge and resistthe formula:

x NH- N=N N= NH x Y SO3H Hogs -Y ance to perspiration. A further advantage of in which one of X and Y is a sulfonic acid these dyes is that when some fading by light radical and the other is a member of the class does occur, the dyes fade on tone, i. e., the faded 30 consisting of hydrogen and methyl.

portions become Weaker but retain the same 3. The coppered tetrasulfo disazo dye having shade as the completely unfaded dye. This the formula:

property makes the dyes valuable as components 4. The coppered tetrasulfo disazo dye having of mixtures of dyes in the preparation of tan, the formula:

taupe, brown and other shades containing some 5. The coppered tetrasulfo disazo dye having gray. the formula: V

X- NE 2,530,431 9 10 in which one of X and Y is a sultonic acid radical 5 52? coppered tri$11110 zO dye halving the OOu-O o u and the other is a member of the class consist- 8. The coppered trisulto disazo dye having the ing of hydrogen and methyl. formula:

HOzS- NH N=N N= NIB-- 0 Ha 50:11 HOaB JOSEPH H. TREPAGNIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,889,732 Stusser et a1 Nov. 29, 1932 2,370,500 Sparks Feb. 27, 1945 2,426,977 Straub et a1 Sept. 9, 1947 2,437,699 Laucius et a1. Mar. 16, 1948 

1. THE COPPERED DISAZO DYES HAVING THE FORMULA: 